Michael Walton (Flight International, 17-23 June) falls short of identifying the drivers for multiple or single engine sourcing by airframe manufacturers.
In respect of multiple sourcing, this provides airframe manufacturers with the advantage of ensuring their aircraft will appeal to a wider market, where airlines may have a preference for a particular engine manufacturer. For this reason, I believe Boeing will not single source the engines for the 7E7 to General Electric.
More likely is collaboration between GE and Pratt & Whitney, with Rolls-Royce remaining independent, as seen on the Airbus A380. This provides for a US engine manufacturer without excluding either of the US competitors, while retaining a European manufacturer for competition. I use the terms European and US guardedly as all engine manufacturers use a worldwide supplier base.
In respect of single sourcing, the cost of developing a new engine is very high. Where an airframe manufacturer seeks to produce a niche market aircraft, the economies of scale make single sourcing the engines more attractive to the engine manufacturer. A case in point is the R-R-powered Airbus A340-500/600. R-R was selected over GE to power this new variant, so GE can hardly be viewed as dominating the market at present.
Ultimately, multiple sourcing of engines is not an efficient use of world resources. Arguably, excessive competition squanders resources that could be better used to benefit the world through enhanced products. Perhaps competition at the aircraft level with single engine sourcing will become the norm in future.
Mike Horswill Derby, UK
Source: Flight International
